The FrameSource class is a source definition of a frame. The values of its attributes represent the initial settings of the frame when it is first called or opened.

When you run a frame, OpenROAD uses the FrameSource's attribute settings to initialize a FrameExec object for the frame. Consequently, many of the FrameExec attributes correspond closely to the FrameSource attributes of the same name. For more information about many of the attributes, see FrameExec Class.

When you use a callframe or openframe statement to run a frame, you can override the FrameExec attributes' settings using the with clause in these statements. However, the new values are enforced only for that instantiation of the frame. OpenROAD does not reset the actual attributes in the FrameSource object.

You can change most of these values dynamically, using the associated FrameExec object (accessed through the CurFrame variable). You also can create and execute frames dynamically by creating a FrameSource object and filling in its attributes at runtime. For an example of this, see the Programming Guide.